ISSN:
1432-0878
Keywords:
Arthropods Limulus
;
Eye
;
Neurosecretion
;
Neuroeffector junction
;
Nerve degeneration
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary In the protocerebrum of Limulus polyphemus, the horseshoe crab, neurosecretory cells are grouped within the curvature of the central body, an association area for inputs from lateral, median, and ventral eyes. Scattered neurohemal terminals face circulatory sinusoids within the brain. Efferent fibers, originating from unspecified, presumably neurosecretory cells in the central nervous system, course through the optic nerves and terminate on pigment and receptor cells of the eyes. Their terminals have a synaptoid structure and their granules have the characteristic density and crystalline substructure of neurosecretory granules. Transection of the lateral optic nerve leads to degranulation and gradual disappearance of terminals and to accumulation of granules at the proximal ends of cut fibers. The Limulus ocular innervation presents a striking example of directed delivery of neurosecretion to pigmentary effector cells, whose adaption is usually controlled by circulating neurohormones.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00307299
Permalink
